Modular 2 (This creature enters the battlefield with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
, Sacrifice an artifact: Search your library for a Construct card, reveal it, put it into your hand, then shuffle your library.

Whenever a Merfolk you control deals combat damage to a player, draw a card.

: Add .
: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with Secret Base.

Flying, vigilance

Enrage — Whenever Silverclad Ferocidons is dealt damage, each opponent sacrifices a permanent.

: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

, Sacrifice another creature: Put a +1/+1 counter on Skyclave Shadowcat.
Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

When Split Screen enters the battlefield, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it.
Play with your libraries' top cards revealed.
When Split Screen leaves the battlefield, shuffle your libraries together.

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on Sprite Dragon.

Until end of turn, target creature becomes a blue Serpent with base power and toughness 4/4.
Cycling (, Discard this card: Draw a card.)

Steel Leaf Champion can't be blocked by creatures with power 2 or less.

Whenever you augment, enchant, or mutate a creature you control, draw a card.
: Add , , , , or .

Whenever you augment, enchant, or mutate a creature you control, draw a card.
: Add , , , , or .

, : Creatures you control get +1/+0 and gain menace until end of turn. (They can't be blocked except by two or more creatures.)
, : You gain 2 life.

Instant, sorcery, and Dragon spells you control can't be countered.
Whenever you cast an instant or sorcery spell from your hand, if Taigam, Ojutai Master attacked this turn, that spell gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Skip your draw step.
At the beginning of your upkeep, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
, , Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

Whenever Two-Headed Giant attacks, flip two coins. If both coins come up heads, Two-Headed Giant gains double strike until end of turn. If both coins come up tails, Two-Headed Giant gains menace until end of turn.

Search your library for up to X creature cards with different names that each have converted mana cost X, reveal them, put them into your hand, then shuffle your library.

: Add . Spend this mana only to cast spells with watermarks.

Kicker (You may pay an additional as you cast this spell.)
Put a +1/+1 counter on each creature you control. If this spell was kicked, put two +1/+1 counters on each creature you control instead.